Siebel Systems was the undisputed dominant CRM software vendor, peaking at 45% market share in 2002. Since being acquired by Oracle in 2005, the product has continued its assertive push however with stiff competition from arch rival SAP, and multiple ways to measure market share, both Oracle and SAP claim top CRM software industry position. Most analysts give Oracle a slight edge, however, it largely comes down to what variables are used and benchmarks are counted.

Oracle Siebel is an impressive enterprise-level customer relationship management application. The product's roots were deep in Sales Force Automation (SFA), however, over several years Siebel Systems acquired or built-out a broad CRM suite as well as dozens of purpose-built vertical market CRM solutions.

Oracle Siebel, like almost all other client-server CRM software, has a reputation for high risk, and very expensive, deployments—leaving this enterprise software solution largely for enterprise-level customers. In fact, failed implementations and frustrated users are the primary impetus for the rise and sky-rocketing growth of cloud or software as a service (SaaS) CRM systems. Not to be left out of a major market movement, Oracle also offers its Oracle CRM on Demand for SaaS CRM prospects.

The SAP CRM solution is a fully integrated customer relationship management (CRM) software manufactured by SAP AG that targets business software requirements of midsize and large organizations for nearly all industries and sectors.

Similar to competitor Oracle, SAP has more recently released a SaaS CRM product, called SAP Sales on Demand. However, this online solution is far more designed to extend the on-premise products than transition SAPs install base to the cloud.

For customer seeking wholesale transition to the cloud, SAP offers their Business ByDesign SaaS solution. Business ByDesign is a purpose built cloud solution covering both ERP (Enterprise Resource Planning) and CRM—an enterprise-wide business suite hosted from Germany and completely in the cloud.

Salesforce.com is still the new guy, but no longer the small guy. The company is now the third largest CRM software publisher. While not the size if its major competitors—such as Oracle, SAP or Microsoft—it has nonetheless acquired over 2 million global customers.

Salesforce.com has become a leading provider of customer management software applications delivered via the software-as-a-service or cloud computing model. The company's flagship solution is a customer relationship management (CRM) system designed for businesses of all sizes and industries worldwide.

Salesforce also provides a platform-as-a-service (PaaS) solution called Force.com and manages a portfolio of integrated third party systems in an online ecosystem it calls AppExchange. Salesforce.com markets its CRM and enterprise software solutions to businesses on a subscription basis, primarily through a direct sales model but also indirectly through a business partner channel.

Microsoft is the number four CRM market share leader. As is often the case with Microsoft, it takes them four versions to get it right.

Microsoft Dynamics CRM 2011 is the 5th product version release for the customer relationship management software solution. Some pundits point out that there was never a version number two and Microsoft accelerated their version count as they skipped from version one to version three. However, with the most recent name change from CRM 5 to Dynamics CRM 2011, Microsoft has moved away from the sequential version numbering scheme.

Microsoft CRM is unique in an increasingly crowded CRM software marketplace as the same code set can be implemented on-premise or used in the software-as-a-service (SaaS) remote delivery model. Also, customers have the option to subscribe to Dynamics CRM directly from Microsoft or may choose from a plethora of specialized Microsoft partners.

The company's most recent release now allows SaaS customers and business partners to install sever-side code in the Microsoft cloud and data centers. Microsoft's CRM offering will also continue to advance in combination with Azure, its high profile public cloud. Additional unique Microsoft CRM product strengths include seamless integration with MS Outlook, Office & SharePoint; highly configurable role-based workflows; business intelligence (BI) and analytics; and a suite of strong technology tools for software integration and customization.

RightNow doesn't match the company size or global brand power of the prior four CRM vendors, but nonetheless is the number five market share leader and a formidable competitor in its particular target markets.

RightNow is a provider of on-demand CRM and customer experience solutions that aid B2C consumer-centric organizations deliver consistently great customer experiences. The company boasts a mission to "rid the world of bad experiences one consumer interaction at a time, 8 million times a day."

Headquartered far from Silicon Valley in remote Bozeman, Montana, RightNow is not your typical software technology player—in fact far from it. While most of the market share leading CRM software vendors trace their roots to sales force automation (SFA), RightNow was instead born to deliver deep customer service. And while most CRM companies strive to get continually broader and grow their software footprints into platform stacks and back-office accounting and ERP systems, RightNow focuses on more of a best of breed, customer experience journey.